Grinding wheel truing apparatus



June 17, 1952 L. J. LALIME GRINDING WHEEL TRUING APPARATUS 3Sheets-Sheet 1 Filed Sept. 5, 1946 June 17, 1952 L. J. LALIME 2,600,548

GRINDING WHEEL TRUING' APPARATUS Filed Sept; 5, 1946 3 Sheets-Sheet 2INVENTOR June 17, 1952 J. LALIME 2,699,543

GRINDING WHEEL TRUING APPARATUS Filed Sept. 5, 1946 3 Sheets-Sheet 5 a\D N Patented June 17, 1952 eeelieeieee pi mee 5, 94 seie i fle-ee ifThe pre ent inxeption xele te togpngmvemente in e j'i qin' Wh t His 2 pinc pa o v w. de endvel'and Limnmxed ndi g wheel tryin ap a atus naming.2 pl a li y 9 twine device a apte v r ,h 'uin vb el 'q ye y incl nedperipheral grinfi ir f .a ehpl sie .inding wheel to cause feces" 1:9 Jgetrged w t accurac mid a n, m p edete mined an le with ,l elajiion fio neanggher} his a ur he obj ct of Ja iny mi n .1 p id a nove n mm yied t ie -en er tt e o is e fieral descri fi lll ada ted vtrui j x the faces ofe equa vt u- H V .Q m valq s cran wheel for .the filmin me re eeeiiveieme er and s eu de .2 Mine cs we a whis h pxoyisicnn mafia me we em,potions ofth whee um pleyices 1n; m'we manner to QQntIpI theihi ghdegree of accuracy required, the size Of the included angle betwe n.tlge en ndm i qe T m chine 2 ed in t e d wings a mbbdyijn in i q mklgei e e a 'i u s o flie .inv i qpl pri e Ia sh ld nd n .me iii e o t phav n a w rk .tahl a In d him ,fi enelat ymovements .meansi r 1:9 ampl'SHpPQ j ng 1 Wor th .o .a c oss slide. em gta g ind ng wheel Spindlevin i @13 e li l et en a n an t the axis of rp atibnfif th w d .Tlcroes' slide 911 .which'gge spiridle'is rrgour jge d fcr hou de etinqi eThe W n e exews Pre iew i e e rda c With th inv ntien; m innise' a fimin evic which i mounted il iiml .si e j he g dme wh e or .mwememlw t 1'w eu e t fortruin the metereexiphera rind ng eu e cf t .8)" en L 9.twine s e e which is1mou edet't. rea id .Q xtbe gr ndin w e for l i efihe' 1 el ferin in i v ei 0f ithe wi eel. The 12 eel a e mount d i9.cause the mnekmp w 9 'amete and hoqlde sired eagl wit re including {thetru ihg es is s1 i h t at the lan .0: moyem efe hp mig .tppl w t ea onto .th .e tieclie li e i 'l z esi @1 3 t parts vam ie y :21 m."fed- Dr vnteny pe i't e er e m me el rei e e 1 Mine. e-

'yices.

Further in accordance with the invention,

means a e pr qed cfqfefl q ing e emn ular adjustment of me rin e he? E eide .Q me me hin f siz c the "iiihi'de' i a r angle between gmeter enq's hou-l er r1 ding surfces' of @eva tae" thit -it W th t 'a'b iew as mayhe'i 0 feapuree of ighe inventipn; Fig. 2 is a ifragmentary gene ehdwv aShoulder gmqing' machine1similair 13o Athafi;

40 Egg. 1:, egibepi: ftl-iat fllthe grindizig wheel ing devices; Fig. 6illustrating a grinding wheel having its axis set at a 45 degree anglefor the grinding of a shoulder when. the included angle is exactly 90degrees, this being the arrangement shown in greater detail in Fig. 1;Fig. 7 being similar to Fig. 6, but with the grinding wheel axis tiltedslightly to produce a slightly less than 90 degree included anglebetween the inclined grinding surfaces; Fig. 8 being similar to Fig. 6,but with the grinding wheel axis tilted slightly in the oppositedirection to produce a slightly greater than 90 degree included anglebetween the inclined grinding surfaces; Fig. 9 illustrating a grindingwheel having its rotational axis set at a 30 degree angle from the axisof rotation of the work, and with the truing devices arranged to producean included angle of 120 degrees between the inclined grinding surfaces;and Fig. 10 illustrating a grinding wheel with its axis of rotation setat degrees from the axis of rotation of the work, and with the truingdevices arranged to produce a 90 degree included angle between theinclined grinding surfaces.

Referring to the drawings, the illustrated machine comprises a basegenerally indicated at I0, a transversely movable slide support l2 whichcarries on a swivel mounting (not shown) a work table l3 having thereona headstock l4 and a footstock [6, a grinding wheel support in the formof a cross slide 18 adapted for movement at right angles to the Worktable 18, and a grinding wheel 28 having its axis of rotation set at anangle to the plane of movement of the work. The work table is movablysupported on a slideway comprising a Vshaped way 22 and a fiat way 24,

translatory movement being imparted to the table by means of feedconnections which may be of ordinary description including a cylinderand a piston on a piston rod generally indicated at 26. The cross slideI8 is supported for sliding movement on a way generally indicated at 38,and is adapted to be moved toward and away from the work throughconnections which include a cross feed screw 32, a nut formed in 2.depending lug 34 on the cross slide 18 and a hand wheel 38 at the frontof the machine. The grinding wheel 28 is mounted on a spindle 48 whichcarries at its other end a pulley 42 connected through belts M and apulley 48 to be driven from an electric motor 48.

In accordance with a feature of the invention, the grinding wheelassembly above described, is supported on the cross slide I8 in a mannerto permit of a slight angular adjustment of the grinding wheel withrelation to the truing devices of the machine hereinafter to bedescribed. To this end, a swivelling wheel spindle supporting plate 52is mounted to turn about a swivel 54 on the cross slide l8, and isformed with an upwardly extending standard 56 which provides a bearingfor the grinding wheel spindle 48 and with a supporting bracket 58 towhich is secured the spindle motor 48. In the embodiment of theinvention shown in Fig. l of the drawings, in which the grinding wheelspindle is set at approximately a degree angle to the work, a mechanismfor adjusting the angular position of the support 52 and the grindingWheel 20 is provided, which comprises an adjusting worm 88 and Wormsupporting shaft 62 which is mounted at the rear of the cross slide 48in lugs 64, 68. The worm 68 engages the teeth of a worm gear segment 68formed in the rear end of the swivel support 52. The swivel support 52is rigidly secured in adjusted position with relation to the cross 4slide 18 by means of a series of clamping machine screws 10, I2, 14, I6and 18, which extend through slots in the swivel support 52, and arescrewthreaded into the face of the cross slide 18. The slots referredto, are disposed circumferentially of the swivel 54 and permit theswivel support 52 and grinding wheel 20 to be adjusted angularly in eachdirection by a small amount approximating three degrees with relation tothe cross slide 18.

In the embodiment shown in Figs. 1, 2 and 3 of the drawings, thegrinding wheel spindle 40 and grinding wheel 28 are set with therotational axis at a 45 degree angle with the work, and the grindingwheel is formed with two inclined surfaces including a diameter grindingsurface for grinding the peripheral surface of the work along the axisthereof, and a shoulder grinding surface 82 disposed at a degree anglewith relation to the diameter grinding surface 80. A truing device whichmay be of ordinary description, is provided for truing the diametergrinding surface 88, said device comprising generally a support 84 whichis adapted to be mounted on the work table 13, and a truing tool 88. Inaccordance with the invention, a separate truing device is provided fortruing the shoulder grinding surface 82, comprising a bracket 88 whichis adapted to be mounted on the work table l3, and carries thereon atruing tool support 98 and a truing tool 92 adapted for engagement withthe shoulder grinding surface 82 of the grinding wheel at the rear sideof the wheel. As best shown in Figs. 1 and 2, the tool support 98 ismounted for adjustment on a guideway 94 formed on the support 88 at a 45degree angle to the axis of rotation of the work, so that the truingtool may be adjusted along a line extending radially of the grindingwheel. An adjusting screw 95 having a knurled head 98 screw-threaded tothe tool support 98 and supported against axial movement in a bearingI80 at the end of guideway 94 provides a convenient means of adjustmentof truing tool 92.

The operation of the truing apparatus above described, and particularlyillustrated in Figs. 1 to 3 of the drawings, may be briefly described asfollows: The truing device comprising truing tool 86 for truing thediameter grinding surface of the wheel, and the shoulder truing devicecomprising truing tool 92 for truing the shoulder grinding surface, arelocated in their adjusted position preparatory for the truing operationwhich is performed while the grinding wheel is running by effecting atranslatory movement of the sliding support l2 and work table 13 thereonto the right, so that the truing tools 86 and 92 respectively, arecaused to engage with and true the respective diameter and shouldergrinding surfaces. In order that these surfaces, and more particularlythe shoulder grinding surface 82 may be trued to precisely the desiredangle, an adjustment or correction may be made in the angular positionof the swivel support 52 and grinding wheel 20 mounted thereon byloosening clam-ping screws 16 to 18 inclusive, and thereafter byrotating the worm shaft 62 and worm 68. Diagrammatic Figures 6 to 8inclusive of the drawings, indicate the manner in which this correctionis made. Fig. 6 illustrates a truing operation under conditions in whichthe grinding wheel spindle 48 is set at exactly a 45 degree angle to theplane of movement of the work support, and in which the included anglebetween the diameter and shoulder grinding surfaces is exactly 90degrees. In the event that inspection of work previously completed onthe machine, indicates that the grinding surface should be trued to aslightly smaller included angle, the swivel support 52 and grindingwheel assembly thereon may be swung slightly in a counterclockwisedirection through a small angle. In the drawings, an adjustment of threedegrees is indicated, and in which the grinding wheel spindle 46 is setfrom a 45 to a 48 degree angle with relation to the plane of movement ofthe work. Under these conditions the diameter grinding surface 85 willbe trued in the normal manner to a plane parallel to the direction ofmovement of the work support, while the surface '82 will be trued to aless than 90 degree angle with the diameter grinding surface 80.Similarly, if the desirability of a greater than 90 degree includedangle is indicated, adjustment of the grinding wheel assembly includingthe swivel support 52 and grinding wheel 26 may be effected in aclockwise direction, so that the grinding wheel spindle axis is set from45 to 42 degrees with relation to the :plane of movement of the worksupport. The diameter grinding surface 85 is again trued to a planewhich is parallel to the direction of movement of the work support,while the shoulder grinding surface 92 is trued to a greater than 90degree angle with the shoulder grinding surface 82. While in thedrawings, a range of adjustment of three degrees in each direction isindicated, it will be understood that any range of adjustment larger orsmaller than that indicated may be employed if so desired.

Figs. 4 and 5 of the drawings, illustrate a modified form of truingapparatus embodying the several features of the invention, which isadapted for the truing of a shoulder grinding wheel having the axis ofrotation of the wheel set at a 30 degree angle from the plane oftransverse movement of the work. In this form of the invention, thegrinding wheel assembly including a grinding wheel III], a grindingwheel spindle H2, pulleys H4 and H6, belts II 8 and motor I26, arecarried in a swivel support I22 with the spindle and grinding wheel setat a 60 degree angle from the plane of movement of the cross slide I8,and at a 30 degree angle from the plane of movement of the slide supportI2 and work table I3. Angular adjustment of the position of the swivelsupport I 22 and of the grinding wheel assembly thereon is obtained bymeans of a worm shaft I24 mounted at the forward end of the cross slideI8 in lugs I26, I28, and a worm I36 which engages with a worm gearsegment I32 cut in the forward end of the swivel support I22. In theembodiment of the invention illustrated in Figs. 4 and 5, the swivelsupport I22 is rigidly clamped in adjusted position by means of a numberof clamping screws designated at I34, I36, I33, I49 and I42 which extendthrough slots formed in the swivel support I22, and are screwthreadedinto the cross slide I8.

The truing devices provided for this form of the invention, comprise thetruing tool 86 carried on its bracket 84 on the work table I3 for thetruing of the diameter grinding surface indicated at 244 of the grindingwheel I I0. The mechanism provided for this form of the invention fortruing the shoulder grinding surface of the wheel designated at I45,comprises a truing tool I46 which is supported and arranged forengagement with a portion of the grinding wheel diametrically oppositethat engaged by the diameter surface truing tool 86. The truing tool I46is mounted in a holder I 48 adjustably supported in a housing I50 whichis in turn mounted for sliding movement on ways I52 on a bracket I 54fixed to a transverse abutment I56 on the cross slide I8. The holder I48is shifted radially toward the grinding wheel by means of a positioningscrew I58 connected at its rear end by bevel gears I60 with a verticalshaft I62 which is in turn connected through bevel gears I64 with ahorizontal actuating shaft I66. At its forward end the shaft I66 isformed with a hand wheel I68. For moving the tool holder I46 across theface of the grinding wheel, driving connections are provided in the formof a driving screw I16 which is screw-threaded into the base of thehousing I50 and supported against axial movement to turn in a bearingprovided in an upwardly extending flange I12 of bracket I54. The screwI16 is driven by means of an electric motor I14 through connectionswhich comprise a belt I16 which passes around a pulley I18 driven fromthe motor I14 and around a pulley I carried on the screw shaft I16.Control of the motor I14 to cause the diamond tool holder I46 to dressthe shouldered surface of the grinding wheel may be effected by anysuitable electric circuit to the motor I14 as, for example, one which isresponsive to switches on panel I84 (Fig. 4) with separate controlbuttons marked respectively Stop, Start and Reverse. The operation oftruing the shoulder grinding surface of grinding wheel I I it is readilyperformed either during the operation of truing the diameter grindingsurface or independently thereof.

The relationship of the grinding wheel I I 0 and the two truing tools 86and I46 for the truing of the diameter grinding surface I44 and shouldergrinding surface I45 of the grinding wheel IIG set at a 30 degree anglefrom the work in accordance with the disclosure of Figs. 4 and 5, isparticularly illustrated in diagrammatic form in Fig. 10. From aninspection of Fig. 10, it will be appreciated that in order to obtain a90 degree in cluded angle of the grinding surfaces I44 and I45, thetruing tool I46 must move in a plane which is inclined 60 degrees to theaxis of rotation of the wheel III] and 30 degrees from the plane ofmovement of the slide support I2 and work table IS. A maximum rigidityof the supporting slide for the shoulder truing tool I46 is obtained bymounting the shoulder truing device directly upon the cross feed slideI8 which also carries the grinding wheel assembly. A truing device ofthe general type illustrated in Figs. 4 and 5, for the truing of theshoulder grinding surface of the wheel I I0 is of general applicationand is capable of use in the manner herein described for any angularsetting of the grinding wheel and grinding wheel spindle with relationto the cross feed slide and work support, and for the truing ofrelatively inclined diameter and shoulder grinding surfaces of whateverincluded angle. In the event that a truing device of this general typeis employed for the truing of a shoulder grinding surface of a wheel setat a 45 degree angle as shown in Figs. 1 and 3, the tool support slidewill then be supported on ways to move in a plane parallel to that ofthe work support. Any inaccuracy which might be found to exist in theangular relation of the machined supporting ways for the work table andthe shouldered truing tool support is quickly and easily compensated forby a compensatory adjustment in the angular position of the swivelsupport I22 and the grinding wheel assembly mounted thereon.

Diagrammatic Fig. 9 of the drawings illustrates still another form .ofthe shoulder grinding wheel in which the wheel is set at a 30 degreeangle from the plane of movement of the work support, and in which theshoulder surface truing tool and the diameter surface truing tool aremaintained in parallel relation, to produce an included angle of 120degrees between these surfaces. As in the instances previouslydiscussed, an adjustment of the included angle to the most exactingstandard is readily obtained by an appropriate angular adjustment of thegrinding wheel assembly with its swivel support upon the cross slide [8.

While an illustrative form of the invention has been described inconsiderable detail, it will be understood that numerous changes in theconstruction and arrangement of the several parts and in the generalapplication of the invention may be made, without departing from itsprinciples and scope. The terms and expressions used herein have beenemployed as terms of description and not limitation.

What is claimed is:

1. In a grinding machine having a work support and a grinding wheelcarriage supported on the machine for relative cross and translatorymovement on the machine, rotary work supporting means on the worksupport, a spindle support mounted swivelly on the grinding wheelcarriage at right angles to the directions of said cross and translatorymovement, a grinding wheel spindle mounted on said swivel support, and agrinding wheel mounted on the spindle having relatively inclinedabrading surfaces for work periphery and shoulder grinding, thecombination of a truing attachment for truing said relatively inclinedabrading surfaces to a predetermined included angle at a single settingof the grinding wheel and truing attachment, which comprises a workperiphery truing tool mounted on the machine for movement in saidtranslatory path and positioned for movement across said work peripheryabrading surface in truing engagement therewith, a shoulder truing toolmounted in the machine to move in a linear path angularly related tosaid translatory path and positioned for movement across the workshoulder abrading surface in truing engagement therewith at the oppositeside of the spindle from the work periphery truing tool, said shouldertruing tool being further supported from the machine for shiftingmovement transversely of said path against the shoulder abrading surfaceof the wheel, and means securing the swivel spindle support to thecarriage in a position of fine angular adjustment to determine theincluded angle between the periphery and shoulder abrading surfaces.

2. In a grinding machine having a work suppor and a grinding wheelcarriage supported on the machine for relative cross and translatorymovement on the machine, rotary work supporting means on the worksupport, a spindle support mounted swivelly on the grinding wheelcarriage at right angles to the directions of said cross and translatorymovement, a grinding wheel spindle mounted on said swivel support, and agrinding wheel mounted on the spindle having relatively inclinedabrading surfaces for work periphery and shoulder grinding, thecombination of a truing attachment for truing said relatively inclinedabrading surfaces to a predetermined included angle at a single settingof the grinding wheel and truing attachment, which comprises a workperiphery truing tool mounted on the work support for movement in saidtranslatory path for truing said work periphery abrading surface, a

shoulder truing tool support mounted in the machine to move in a linearpath angularly related to said translatory path across the work shoulderabrading surface at the opposite side of the spindle from the workperiphery truing tool, said shoulder truing tool support being furthersupported from the machine for shifting movement transversely of saidpath against the shoulder abrading surface of the wheel, a shouldertruing tool mounted on said shoulder truing tool support, and meanssecuring the swivel spindle support to the carriage in a position offine angular adjustment to determine the included angle between theperiphery and shoulder abrading surfaces.

3. In a grinding machine having a work support and a grinding wheelcarriage supported on the machine for relative cross and translatorymovement, rotary work supporting means on the work support turning on anaxis extending in the direction of said translatory movement, a spindlesupport mounted swivelly on the grinding wheel carriage at a right angleto the directions of said cross and translatory movements, a grindingwheel spindle mounted on said swivel support, a grinding wheel mountedon the spindle having relatively inclined abrading surfaces for workperiphery and shoulder grinding, the combination of a truing attachmentfor truing said relatively inclined abrading surfaces to a predeterminedincluded angle at a single setting of the grinding wheel and truingattachment, which comprises a work periphery truing tool mounted on thework support for movement in said translatory path for truing said workperiphery abrading surface, a shoulder truing tool mounted on the worksupport at the opposite side of the spindle from the work peripherytruing tool to move in said translatory path across the shoulderabrading surface, said shoulder truing tool being further supported onthe work support to move transversely of said translatory path foradjustment of the shoulder truing tool against the shoulder abradingsurface of the Wheel, and means securing the swivel spindle support tothe carriage in a position of fine angular adjustment to determine theincluded angle between the periphery and shoulder abrading surfaces.

4. In a grinding machine having a work support mounted for translatorymovements in the machine, a rotary work supporting means on the worksupport turning on an axis extending in the direction of saidtranslatory movement, a grinding wheel carriage mounted on the machinefor cross feeding movement toward the work support, a spindle supportmounted swivelly on the grinding wheel carriage on an axis at rightangles to the carriage, a grinding wheel spindle on the swivel support,a grinding Wheel on the spindle having relatively inclined workperiphery and shoulder abrading surfaces, the combination of a workperiphery truing tool mounted on the work support for movement in saidtranslatory path for truing said work periphery abrading surface, ashoulder truing tool support mounted on the work support at the oppositeside of the spindle from the periphery truing tool, a shoulder truingtool mounted on said shoulder truing tool support to move with the worksupport in said translatory path across the shoulder abrading surface, aguideway on the work support on which the shoulder truing tool supportis adjustable along a path directed radially toward the axis of thegrinding wheel spindle, actuating 9, means connected between the worksupport and shoulder truing tool support for moving the shoulder truingtool against the shoulder abrading surface of the wheel, and meanssecuring the swivel support to the carriage in a position of fineangular adjustment to determine the included angle between the peripheryand shoulder abrading surfaces. 7

- 5. In a grinding machine having a work support, rotary work supportingmeans on the work support, and a grinding wheel assembly including agrinding wheel carriage on the machine. a spindle support mountedswivelly on the grinding wheel carriage at right angles to the carriage,a grinding wheel spindle mounted on said swivel support, and a grindingwheel on the spindle having two relatively inclined work periphery andshoulder abrading surfaces, said work support and grinding Wheelcarriage being mounted on the machine for relative cross and translatorymovements, the combination of a dressing attachment for dressing saidrelatively inclined abrading surfaces on'the grinding wheel to thedesired angles at a single setting which comprises a truing devicemounted on the work support at the work engaging side of the grindingwheel spindle including a work periphery truing tool carried on the worksupport and movable relatively to the grinding wheel in a fixed pathfollowing the direction of said translatory movement for truing saidwork diameter abrading surface, a second truing device comprising ashoulder truing tool, a shoulder support on which said shoulder tool ismounted on the carriage movable in a fixed path for truing engagementwith the other of said abrading surfaces at the opposite side of thegrinding wheel from the work periphery truing tool, actuating meansconnected with said shoulder tool support to move said shoulder toolsupport and shoulder truing tool in said path, and fine gauge adjustingmeans controlling the angular position of the swiveling spindle supportand grinding wheel spindle on the carriage.

6. In a grinding machine having a work support and a grinding wheelcarriage supported on the machine for relative cross and translatorymovement, rotary work supporting means on the work support turning on anaxis extending in the direction of said translatory movement, a grindingwheel having relatively inclined work periphery and shoulder abradingsurfaces, a grinding wheel spindle on which the grinding wheel ismounted, and a spindle support on the carriage on which the wheelspindle is supported for swiveling adjustment with relation to thedirections of said cross and translatory movement, the combination of adressing attachment for dressing the relatively inclined Work peripheryand shoulder abrading surfaces of said grinding wheel which comprises awork periphery abrading surface truing device on the work support at thework engaging side of the grinding wheel spindle including a truing toolresponsive to the relative translatory movement of the work support andcarriage for truing said work periphery abrading surface, a shoulderabrading surface truing device disposed at the opposite side of thegrinding wheel spindle from the periphery abrading surface truing devicecomprising a shoulder truing tool support mounted in the machine formovement in a path of predetermined fixed direction, and a shoulderabrading surface truing tool mounted on the tool support for movement insaid fixed path across said shoulder abrading surface, and adjustingmeans controlling the swivel position of the swivel support and grindingwheel to vary the included angle between said relatively inclined workperiphery and shoulder abrading surfaces.

7. In a grinding machine having a work support mounted in the machinefor translatory movement, rotary work supporting means on the worksupport turning on a horizontal axis, and a grinding wheel assemblyincluding a grinding wheel carriage mounted in the machine for crossfeeding movement, a spindle support mounted swivelly on the grindingwheel carriage on a vertical axis, a grinding wheel spindle mounted onsaid swivel support to turn on a horizontal axis set at approximately aangle to the direction of said translatory movement, and a grindingwheel on the spindle having relatively inclined work periphery andshoulder abrading surfaces, the combination of a work periphery surfacetruing device comprising a work periphery abrading surface truing tool,and means supporting said tool on the work support at the work engagingside of the grinding wheel spindle, a shoulder surface truing devicecomprising a shoulder truing tool support mounted on the work support,and a shoulder abrading surface truing tool mounted on the said shouldertruing tool support engaging a portion of the shoulder abrading surfaceof the grinding wheel at the opposite side of the grinding wheel spindlefrom the work periphery abrading surface truing tool, and adjustingmeans controlling the angular position of the swiveling support andgrinding wheel spindle on the grinding wheel carriage to vary theincluded angle of said relatively inclined abrading surfaces.

8. In a grinding machine having a work support mounted in the machinefor translatory movement, rotary work supporting means on the worksupport, and a grinding wheel assembly including a grinding wheelcarriage mounted in the machine for cross feeding movement, a spindlesupport mounted swivelly on the grinding wheel carriage on an axis atright angles to the carriage, a grinding wheel spindle mounted on saidsupport, and a grinding wheel mounted on the spindle having relativelyinclined work periphery and shoulder abrading surfaces, the combinationof a truing device comprising a work periphery abrading surface truingtool mounted on the work support and engaging a portion of the workperiphery abrading surface of the wheel at the work engaging side of thegrinding wheel spindle and acting to true said work periphery abradingsurface, a shoulder abrading surface truing device disposed at theopposite side of the wheel spindle from the first mentioned truingdevice comprising a shoulder abrading surface truing tool, a shouldertruing tool support slidably supported on the grinding wheel carriagefor movement along a fixed path a-ngularly related to the direction ofsaid translatory movement of the work support, an electric motor, anddriving connections from the motor to move said slidable support andtruing tool across the shoulder abrading surface, and adjusting meanscontrolling the angular position of the spindle support on the carriageto vary the included angle of said work periphery and shoulder abradingsurfaces.

9. In a grinding machine a combination in accordance with claim 8 inwhich the shoulder truing device comprises a guideway on the spindlecarriage, a shoulder truing tool supported on the guideway for movementalong the line of movement followed by the truing tool across theshoulder abrading surface, and a-tool holder movably supported on theshoulder truing tool support for adjustment in a directionperpendicularly toward and away from the grinding wheel axis, andactuating means on the machine connected with the work truing shouldersupport operable to move the shoulder truing tool support in theguideway for truing said shoulder abrading surface.

10. In a grinding machine having a work support supported fortranslatory movement, rotary work supporting means on the work supportturning on an axis extending in the direction of said translatorymovement, and a grinding wheel assembly including a grinding wheelcarriage supported on the machine for cross feeding movement toward thework support, a spindle support mounted swivelly on the grinding wheelcarriage on an axis at right angles to the carriage, a grinding wheelspindle mounted on said support, said spindle being disposed on thecarriage with its axis at approximately a 30 angle from the direction ofsaid translatory movement, and a grinding wheel having relativelyinclined work periphery and shoulder abrading surfaces, the combinationof a work periphery abrading surface truing device comprising a workperiphery abrading surface truing tool mounted on the work support, ashoulder abrading surface truing device disposed at the opposite side ofthe grinding wheel spindle from said work periphery abrading surfacetruing device comprising a shoulder abrading surface truing tool, a

12 support on which said shoulder surface truing tool is mounted, and aguideway on the grinding wheel carriage on which the shoulder truingtool support is movable to true said shoulder abrading surface at a 90included angle with relation to the work periphery abrading surface ofthe wheel, actuating means on the machine connected with the toolsupport operable to move said tool support on its guideway, andadjusting means controlling the angular position of the wheel spindlesupport on the carriage to vary the included angle of said trued workperiphery and shoulder grinding surfaces LESTER J. LALIME.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,769,143 Koskinen July 1, 19301,871,504 Einstein Aug. 16, 1932 2,004,426 Booth July 11, 1935 2,178,842Paine Nov. 7, 1939 2,272,088 Hultgren Feb. 3, 1942 2,287,701 Nelson June23, 1942 2,323,401 Johnson July 6, 1943 FOREIGN PATENTS Number CountryDate 451,465 Germany Oct. 31, 1927

